1. Field of the Invention
The present invention relates to a highly water-resistant, environmentally friendly, low power-consumption line glower adapted to be driven with a small power.
2. Description of Related Art
Conventionally, a neon tube, fluorescent tube, etc. are used as a line glower or light emitter which can provide a linear light source extending over a distance of several meters.
However, the neon tube or fluorescent tube needs a high voltage, and it may possibly cause an electric shock or a current is likely to leak from it. Therefore, it cannot be used in water, rain or snow. Further, since it is formed from a glass tube, it may not be used in a place where it will possibly be broken by collision with a person, car or the like. The glass tube is very fragile.
For a circular shape, the glass tube has to be elaborately bent or curved in conformity to the curvature of the circle. The glass tube bending or curving cannot be easily done but needs a high skill and many experiences. This will increase the manufacturing costs. Furthermore, the neon tube or fluorescent tube consumes a power as large as several tens W per unit length of 1 m. For a long use, a commercial power supply has to be available in a place not far from the neon tube or fluorescent tube.
To solve all the above problems, there have been proposed a light transmission tube comprising a flexible tube and a transparent core solution or soft transparent polymer filled in the tube, and a braided plastic optical fiber product.
Briefly speaking, a light generated from a source is admitted into a light transmission tube at one end thereof and let to go out from the lateral side of the tube along a length of several tens meters. Since the light source and glowing portion can thus be separated from each other, the light transmission tube can be used in water, outdoors or in a place where an explosion may possibly take place. Further, the tube will not possibly be easily broken. Different from the glass tubes such as neon tube, fluorescent tube, etc., it needs no troublesome, elaborate working but can be easily worked.
However, when such a conventional light transmission tube is used to emit light from the lateral side thereof along a length of several tens meters, its luminous efficiency is low. For an increased intensity of light, a light source capable of providing an output ranging from 50 to 250 W is required for use with the light transmission tube. Also, when the light source and light transmission tube are used in water, outdoors or in a place where an explosion may possibly take place, the light source should be protected, which will cause the light source itself to have so large a volume as needs a wide space for storage.